Automated Methods for Distinguishing Copies from Original Printed Objects

1. A method, comprising: determining, using a computing device, whether a machine-readable auxiliary signal is embedded in an image of a printed object, wherein determining comprises detecting at least one of a divergence or convergence of at least one characteristic of a set of two or more print structures embedded in the printed object such that the machine-readable auxiliary signal becomes one of more or less detectable, wherein the at least one characteristic changes a detection zone of the auxiliary signal in the image based on the at least one characteristic having a gray level value that varies as a function of location in the printed object; and evaluating the machine-readable auxiliary signal, using the computing device, to determine whether the printed object is an original version of the printed object.

2. The method of claim 1 , wherein the set of two or more print structures comprises a first color and a second color that change differently in response to a copy operation.

3. The method of claim 2 , wherein at least one of the colors corresponds to an ink color that is out of gamut of at least one of a printer or scanner.

4. The method of claim 2 , wherein a difference in luminance of the colors changes in response to the copy operation.

5. The method of claim 1 , wherein the set of two or more print structures comprises a first print structure having a first dot gain characteristic and a second print structure having a second dot gain characteristic, wherein the first print structure is more susceptible to dot gain than the second print structure in response to a copy operation.

6. The method of claim 1 , wherein a difference in luminance of the set of two or more print structures changes in response to a copy operation due to a difference in susceptibility to dot gain of the set of two or more print structures.

7. The method of claim 1 , wherein the set of two or more print structures comprises a first print structure having a first aliasing characteristic and a second print structure having a second aliasing characteristic, wherein the first print structure aliases differently than the second print structure.

8. The method of claim 1 , wherein the machine-readable auxiliary signal is embedded by varying continuity of line structures.

9. The method of claim 1 , wherein one print structure comprises a line segment in a first color, and another print structure comprises a line segment in a second color, wherein the first color is different than the second color.

10. The method of claim 9 , wherein the line segments of the different colors are generated by varying between the first color and the second color along a printed line.

11. The method of claim 1 , wherein the evaluating comprises evaluating a frequency domain metric to detect changes in the print structures.

12. The method of claim 11 , wherein the frequency domain metric is a radial frequency domain metric.

13. The method of claim 11 , wherein evaluating the frequency domain metric comprises evaluating changes in color of a print structure.

14. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising: instructions to determine whether a machine-readable auxiliary signal is embedded in an image of a printed object, wherein determining comprises detecting at least one of a divergence or convergence of at least one characteristic of a set of two or more print structures embedded in the printed object such that the machine-readable auxiliary signal becomes one of more or less detectable, wherein the at least one characteristic of the print structures changes a detection zone of the auxiliary signal in the image based on the at least one characteristic having a gray level value that varies as a function of location in the printed object; and instructions to evaluate the machine-readable auxiliary signal to determine whether the printed object is an original version.

15. The non-transitory computer-readable medium of claim 14 , wherein the set of two or more print structures comprises a first color and a second color that change differently in response to a copy operation.

16. A method comprising: embedding, using a computing device, a machine-readable auxiliary signal in an image at embedding locations using at least one print structure wherein embedding comprises configuring the at least one print structure to change a detection zone of the auxiliary signal in the image, wherein the change causes at least one of a divergence or convergence of at least one characteristic of the at least one print structure such that the machine-readable auxiliary signal becomes one of more or less detectable, and wherein the change is based on the at least one characteristic having a gray level value that varies as a function of location in the image; and creating a metric based at least in part on the machine-readable auxiliary signal embedded in the image, using a computing device, to facilitate detection of the convergence or divergence from a scanned image of a suspect printed object to determine whether the suspect printed object is a copy of a printed object.

17. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising: instructions to embed a machine-readable auxiliary signal in an image at embedding locations using at least one print structure wherein embedding comprises configuring the at least one print structure to change a detection zone of the auxiliary signal in the image, wherein the change causes at least one of a divergence or convergence of at least one characteristic of the at least one print structure such that the machine-readable auxiliary signal becomes one of more or less detectable, and wherein the change is based on the at least one characteristic having a gray level value that varies as a function of location in the image; and instructions to create a metric, based in part on the machine-readable auxiliary signal embedded in the image, to facilitate detection of the convergence or divergence from a scanned image of a suspect printed object to determine whether the suspect printed object is a copy.

18. A method, comprising: determining, using a computing device, whether a machine-readable auxiliary signal is embedded in an image of a printed object, wherein determining comprises detecting at least one of a divergence or convergence of at least one characteristic of at least one print structure embedded in the printed object such that the machine-readable auxiliary signal becomes one of more or less detectable, wherein the at least one characteristic of the at least one print structure changes a detection zone of the auxiliary signal in the image based on the at least one characteristic having a gray level value that varies as a function of location in the printed object, and wherein the at least one print structure comprises a color; and determining, based on evaluating the machine-readable auxiliary signal, using a computing device, whether the printed object is an original version of the printed object.

19. The method of claim 18 , wherein the machine-readable auxiliary signal is embedded by varying continuity of line structures.

20. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising: instructions to determine whether a machine-readable auxiliary signal is embedded in an image of a printed object, wherein determining comprises detecting at least one of a divergence or convergence of at least one characteristic of the at least one print structure embedded in the printed object such that the machine-readable auxiliary signal becomes one of more or less detectable, wherein the at least one characteristic of the at least one print structure changes a detection zone of the auxiliary signal in the image based on the at least one characteristic having a gray level value that varies as a function of location in the printed object, and wherein the at least one print structure comprises a color; and instructions to determine, based on evaluating the machine-readable auxiliary signal, whether the printed object is an original version of the printed object.

21. The non-transitory computer-readable medium of claim 20 , wherein the machine-readable auxiliary signal is embedded by varying continuity of line structures.

22. A device comprising: a memory configured to store an image of a printed object; and a processor operatively coupled to the memory and configured to: determine whether a machine-readable auxiliary signal is embedded in the image of the printed object, wherein determining comprises detecting at least one of a divergence or convergence of at least one characteristic of a set of two or more print structures embedded in the printed object such that the machine-readable auxiliary signal becomes one of more or less detectable, wherein the at least one characteristic of the print structures changes a detection zone of the auxiliary signal in the image based on the at least one characteristic having a gray level value that varies as a function of location in the printed object; and evaluate the machine-readable auxiliary signal to determine whether the printed object is an original version of the printed object.

23. A device comprising: a memory configured to store an image; and a processor operatively coupled to the memory and configured to: embed a machine-readable auxiliary signal in an image at embedding locations using at least one print structure, and wherein embedding comprises configuring the at least one print structure to change a detection zone of the auxiliary signal in the image, wherein the change causes at least one of a divergence or convergence of at least one characteristic of the at least one print structure such that the machine-readable auxiliary signal becomes one of more or less detectable, and wherein the change is based on the at least one characteristic having a gray level value that varies as a function of location in the image; and create a metric, based at least in part on the machine-readable auxiliary signal embedded in the image, to facilitate detection of the convergence or divergence from a scanned image of a suspect printed object to determine whether the suspect printed object is a copy.

24. A device comprising: a memory configured to store an image of a printed object; and a processor operatively coupled to the memory and configured to: determine whether a machine-readable auxiliary signal is embedded in the image, wherein determining comprises detecting at least one of a divergence or convergence of at least one characteristic of at least one print structure embedded in the printed object such that the machine-readable auxiliary signal becomes one of more or less detectable, wherein the at least one characteristic of the at least one print structure changes a detection zone of the auxiliary signal in the image based on the at least one characteristic having a gray level value that varies as a function of location in the image, and wherein the at least one print structure comprises a color; and determine, based on evaluating the machine-readable auxiliary signal, whether the printed object is an original version of the printed object.